Thursday, July 24, 2014

Why we need a Brooklyn Bridge cycle track

I remember when you could walk or bike over the Brooklyn Bridge at almost any hour and not feel crowded. Those days are long past: walking over the bridge has become a major tourist activity, and commuting by bike has become extremely popular. Thanks to hard work by advocates, especially Transportation Alternatives, the city reopened the south sidepath on the Manhattan Bridge to bicycles and pedestrians in 2001, and the north sidepath to bikes in 2004, taking a lot of daily commuters and recreational walkers and joggers off the Brooklyn Bridge.

Even with this additional capacity, the Brooklyn Bridge path gets a lot more cyclists and pedestrians than it can comfortably handle. Pedestrians complain bitterly about the cyclists, and vice versa. Often it is deserved: I've seen many thoughtless cyclists bombing down the offramp, and many clueless pedestrians drifting into the bike lane without looking. But mainly, the pie is too small for all the people who now want a slice. We need more capacity.

There have been proposals in the past to simply ban cyclists from the bridge, and the satirical @bikelobby account on Twitter has capitulated, but often the proposal is to build a new bikeway somewhere on top of the existing bridge structure, as with this 2012 proposal by City Council members Lander, Chin and Levin. I don't think we need to spend that much money; we should simply convert one of the current car lanes to a two-way cycle track.

Converting car lanes to cycle tracks is also not a new thing. It's been done over and over again by the city in the past seven years, first on Ninth Avenue, then Eighth and Kent and now even on the Pulaski Bridge, where the current multiuse path between Greenpoint and Long Island City is similarly strained. This would just be the same thing on the main level of the Brooklyn Bridge, and then the upper multiuse path could be dedicated to pedestrians. It's been proposed for the Brooklyn Bridge before, by Streetsblog commenters and Robert Sullivan.

You might think that the city could not afford to give up that car capacity, but in fact it might wind up increasing the total number of people who cross on the Brooklyn Bridge. There are no buses (or trucks) currently allowed on the bridge. The Manhattan Bridge bike path is well traveled, especially during rush hours, and the number of cyclists can rival the number of cars on nearby lanes.

Last month, at 7:30 on a Tuesday, Clarence Eckerson of Streetfilms took a quick count on the Manhattan Bridge. He counted a hundred cyclists in two minutes and 23 seconds, a rate that corresponds to 2691 2517 vehicles per hour. By contrast (PDF), in 2010 the three outbound car lanes of the Brooklyn Bridge carry 3509 vehicles between 5:00 and 6:00 PM, or 1170 vehicles per lane per hour. The five outbound car/bus/truck lanes on the Manhattan Bridge carried 2382 vehicles, or only 476 vehicles per lane per hour.

In a subsequent tweet, Clarence acknowledged that his sample may not have been representative. "well I am sure that pace didn't hold up!" he wrote. "A dozen were on a tour group" But even if the typical peak counts are not that high (see this PDF from the city DOT), they are probably higher than 476 per hour, and maybe higher than 1170 per hour. This suggests that one of the lanes on the Brooklyn Bridge's main deck would carry more people in the peak rush hour as a two-way cycle track than it currently does as a single car lane.

Clearly there is more research to be done: more samples of peak hour bike and motor vehicle traffic, on both the Brooklyn and Manhattan Bridges. I'm looking forward to the Streetfilm!

10 comments:

If you look at the original configuration of the bridge the inner lanes on either side were first exclusive elevated railway track rights of way. There were only two "vehicular" lanes on either side (total of 4) and of those 4 one on either side had streetcar tracks. When the el service ended around 1940 the tracks were given over to streetcars. The streetcars were removed in the early 1950s when the bridge was rebuilt for automobiles alone. The Bk Br streetcar lines were bustituted at that time and the buses terminated at the High St IND station, where passengers were given a ticket transfer to the IND subway. In so doing (converting the bridge for auto use only) the bridge lost about 3/4 of its carrying capacity.

A proposal I'd often made is to bring bak light rail and put it onto exclusive ROWs on the two inner lanes of the bridge, where the el / streetcar tracks had once been. As a starter, run the line from the LIRR terminal via Flat, Schermerhorn and Bk Br Bl (Adams St), over the bridge and down Bway (back up Trinity Pl) to SF. Most of it should/could be on reserved lanes - no mixing with other traffic. Amongst other things this would free up capacity on the Lex / 7 Ave lines at AA, which are presently absorbing a significant portion of the passengers dumped there by the LIRR.

My office moved last October from midtown to SoHo and the change allowed me to ditch daily use of the Brooklyn Bridge by bike for the Manhattan Bridge. I have to say it's been a huge improvement. Some tourists would get quite aggressive. I tut-tutted once at a woman who'd dumped her bags in the bike lane and she shouted, "This is a tourist area!" at me. Another time, a group yelled at me for going too fast (at 12mph) and interrupting their effort to take wedding pictures in the bike lane.

The existing bridge foot and cycle way is simply way too narrow for everyone trying to use it at the busiest times. It's also pretty stressful at other times when people step into the bike lane to take, for example, selfies. It would make extremely good sense to convert one car lane to a two-way bike lane. Potentially one lane on the other carriageway could be made reversible to absorb some of the displaced traffic.

The bridge is too useful to give up as a cycle facility. It lands riders in a very useful part of town, only half a mile from the Hudson Greenway. Something needs to be done.

Interesting idea, well worth exploring, and nice write-up. But the quantification is sloppy.

Clarence's count of 100 MB cyclists in 143 seconds equates to 2,517 per hour, not 2,691. Far more importantly, that fabulous count shouldn't be extrapolated to a full hour or day -- not when there are full-day counts available from DOT (http://www.nyc.gov/html/dot/downloads/pdf/2013-nyc-cycling-in-the-city.pdf): around 5K/day at the WB, 4K MB, 3K BB.

Of course providing ample space will boost usage. I'm just saying that shaky numbers are a poor foundation for advocacy.

I think the big problem with this is that you'd want to take away a lane on one side of the bridge in the morning, and on the other side in the evening (or at various times, you get the point).

I think a better alternative would be to add one way cycle tracks on each side of the bridge, separate them from the roadway with a jersey barrier, and create two wider lanes with minimal shoulders over the span. With the extra space and fewer lanes you could even build proper exit lanes for the FDR and BQE. The traffic flow improvements might be enough to compensate for the loss of a traffic lane.

Look to the Burrard Bridge in Vancouver for a case study in transforming one lane on a busy bridge to downtown into a cycle track. There was initially a huge amount of political opposition to it, but it worked out spectacularly. No traffic snarls, greatly increased cycling volumes, comfort, speed, and safety.

Thanks for the kind words, Charles, and for catching my error! I put "2.23" minutes in my spreadsheet, when 2'23" is actually 2.38 minutes.

I did caution against extrapolating Clarence's measure to a full hour, but extrapolating it to a daily count is not relevant. The arguments for space allocation are based on peak volumes, not daily volumes.

Hub Bound is based off the September screenline? 2012 that gave 301 on the Brooklyn Bridge, 490 each for the Manhattan and Williamsburg bridges in the 8-9am travel hour. Might have been bad weather, afternoon counts are much lower. Say a better Brooklyn Bridge path gets you as many bikes as the other bridges. Screenline gives about 25 percent higher in August than September. So maybe in the summer you could expect 625 cyclists at peak inbound hour.

Less than the 1421 people (vehicle count is lower) per lane the Brooklyn Bridge handles. Less than the 668 people the Manhattan bridge handles per lane.

But vehicle or person counts per lane isn't the right place to look. Seems like the Manhattan bridge could lose a lane (or two...) and move the same number of cars and trucks, throughput that low the bottleneck most be elsewhere - guess it needed the Lower Manhattan Expressway. If it's not on the Brooklyn bridge then you might be able to lose a lane for free. 1700-1800 vehicles per lane per hour seems doable over the bridge in free flowing traffic.

Although I'm not sure I wouldn't prefer going slow with the tourists over going faster but just a few feet from speeding cars and SUVs, and at the same level as them, even with a jersey barrier. The noise might bother me more than some though.

Peak commute usage doesn't have to be the only consideration. A better tourist trap at noon doesn't have to lose out to some cars in the morning.

With East River bridge tolls, the ramp from I-278 eastbound to the Manhattan-bound Brooklyn Bridge could be closed, as most cars would use the Brooklyn-Battery Tunnel instead. Then the outer lane on the Manhattan-bound side could be transformed into a nice cycle track from Sands Street to the now-closed ramp to Park Row by the police HQ.